CN104319780A - Global reactive voltage optimization method for power transmission and distribution network - Google Patents

Abstract

The invention relates to a global reactive voltage optimization method for a power transmission and distribution network. The method includes the steps that coordinate boundary points of a power transmission network and an active power distribution network are selected; a power transmission network reactive voltage optimization model including complementary constraints is established, and an interior point method is used for solving; the optimization voltage of the power transmission network is converted into a three-phase voltage which is used as the three-phase voltage of an active power distribution network root node; a three-phase reactive voltage optimization model including complementary constraints of the active power distribution network is established, and the interior point method is used for solving; the three-phase optimization power of the active power distribution network is summated and then is used as the corresponding load power of the power transmission network; reactive voltage optimization of the power transmission network and reactive voltage optimization of the active power distribution network are in alternate iteration, when every two adjacent iteration changes of the boundary point power of the power transmission and distribution network meet convergence precision, the global reactive voltage of the power transmission and distribution network is subjected to optimizing convergence, and accordingly a global reactive voltage optimizing strategy is obtained. The problem that the reactive voltage optimization results of the power transmission and distribution network are inconsistent at the boundary points of the power transmission and distribution network can be solved, voltage and power mismatching at the boundary points is eliminated, and reactive resources of the two stages of networks are optimized.

Description

A kind of transmission and distribution network Global optimization method

Technical field

The present invention relates to a kind of power system reactive power voltage optimization method, specifically relate to a kind of transmission and distribution network Global optimization method.

Background technology

Reactive power optimization of power system is under the prerequisite guaranteeing power network safety operation, with generator reactive, on-load transformer tap changer (OLTC), can to exert oneself etc. as control device by switching reactive compensator, realize reactive layered partition balancing, improve grid voltage quality, reduce a kind of optimization method of network loss.

The reactive Voltage Optimum of power transmission network and active distribution network is independently carried out at present mostly separately, carries out equivalence process, can cause power and the voltage mismatch at boundary node place at boundary node place." a transmission & distribution overall situation Load flow calculation " (Sun Hongbin, Zhang Baiming, Xiang Niande. " send out transmission & distribution the overall situation Load flow calculation " 1998,22 (12): 39-42 pages) sum up power transmission network and the power distribution network difference at network configuration and parameter, trend size, model etc." a kind of area power grid new distributed optimal reactive power " (Li Zhongxu, Liu Yutian " Power System and its Automation journal ", 2005,17 (2): 80-83 pages) sum up power transmission network and the difference of power distribution network on idle work optimization, due to the difference of transmission and distribution network network configuration and idle work optimization feature, unified method should not be adopted to build Global Optimized model, but the document does not disclose the access situation of triphase flow and distributed power source in power distribution network aspect.

Along with distributed power source access power distribution network, active distribution network considers have the reactive power of the distributed power source of reactive power compensation planning to combine with traditional voltage-regulation means, realize the reactive Voltage Optimum of active distribution network, optimum results comprises transmission and distribution network boundary node data, the change of transmission and distribution network boundary node voltage and power can be caused, when not coordinating power transmission network and active distribution network, the inconsistent even trend of the possibility of result of power transmission network and active distribution network reactive Voltage Optimum is contrary.In addition, the access of distributed power source can increase the three-phase imbalance of power distribution network, so need to adopt triphase flow computational analysis.

In addition, in the reactive Voltage Optimum of power transmission network and active distribution network containing on-load transformer tap changer, can the control device such as to exert oneself by switching reactive compensator, it is discrete variable in Mathematical Modeling, the reactive Voltage Optimum of power transmission network and active distribution network is mixed-integer nonlinear programming model, and this solves with regard to needing the method considering to process discrete variable.

Therefore power system reactive power voltage optimization needs to consider the optimization of transmission and distribution network Global from the angle of the overall situation, to improve computational accuracy, but world model's Unified Solution can not be built, so will based on the thought of layering and zoning, carry out the composition decomposition of power transmission network and active distribution network reactive Voltage Optimum, the method that employing can process discrete variable solves power transmission network and active distribution network reactive Voltage Optimum model respectively, coordinates to the reactive Voltage Optimum of power transmission network and active distribution network the target reaching global optimization alternately; And in active distribution network reactive Voltage Optimum, consider the Reactive-power control of three-phase imbalance and distributed power source, set up three-phase Optimized model; The data transaction of power transmission network optimum results and active distribution network three-phase optimum results is realized with mutual at transmission and distribution network boundary node place.

Summary of the invention

For the deficiencies in the prior art, the object of this invention is to provide a kind of transmission and distribution network Global optimization method, the method is intended to coordinate power transmission network and active distribution network reactive Voltage Optimum, the voltage of the boundary node that both solutions cause when independently calculating and power mismatch, solve possible inconsistent at transmission and distribution network boundary node of transmission and distribution network reactive Voltage Optimum result, optimize the idle resource of two-level network simultaneously, from the angle of overall united analysis, the complementary Interior-point method that employing can process discrete variable solves power transmission network and active distribution network reactive Voltage Optimum model respectively, the target reaching global optimization is alternately coordinated to the reactive Voltage Optimum of power transmission network and active distribution network, and the data transaction realizing power transmission network optimum results and active distribution network three-phase optimum results at transmission and distribution network boundary node place is with mutual.

The object of the invention is to adopt following technical proposals to realize:

The invention provides a kind of transmission and distribution network Global optimization method, its improvements are, described method comprises the steps:

(1) selected power transmission network and active distribution network orchestration boundary point;

(2) build the power transmission network reactive Voltage Optimum model containing Constraints condition, adopt Non-Linear Programming interior point method to solve it;

(3) be the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network using the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network;

(4) build the three-phase reactive Voltage Optimum model containing Constraints condition of the active distribution network containing distributed power source, adopt Non-Linear Programming interior point method to solve it;

(5) using the load power as power transmission network respective nodes after the summation of the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network;

(6) whether the power the judging transmission and distribution network boundary node in an iterative process change of adjacent twice meets convergence precision, if met, forwards to (7), if do not met, forwards (2) to and continue iteration;

(7) convergence at transmission and distribution network boundary node place according to power transmission network and active distribution network reactive Voltage Optimum, obtains Global optimisation strategy.

Further, in described step (1), selected power transmission network and active distribution network orchestration boundary node, to the modeling of active distribution network three-phase, build the coordination interactive frame of power transmission network and the single-phase reactive Voltage Optimum mixed with three-phase of active distribution network, and the coordination interactive mode of the single-phase reactive Voltage Optimum mixed with three-phase.

Further, in described step (2), take loss minimization as target, node voltage etc. for power transmission network reactive Voltage Optimum model is set up in constraint, adopt the method based on complementary theory and Non-Linear Programming interior point method that can process discrete variable to solve it; Power transmission network reactive Voltage Optimum model is as follows:

min f(x)＝P _l

$s.t.P_i=P_{\mathrm{gi}}-P_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}}+B_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}})$

$Q_i=Q_{\mathrm{gi}}-Q_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}}-B_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}})$

V _i ^min≤V _i≤V _i ^max 1)；

Q _gi ^min≤Q _gi≤Q _gi ^max

Q _ci ^min≤Q _ci≤Q _ci ^max

T _ki ^min≤T _ki≤T _ki ^max

Wherein: P _lfor the network loss of transmission system; N is transmission system nodes; P _iand Q _ibe respectively injection active power and the reactive power of node i; P _giand P _libe respectively generator active power and the load active power of node i; Q _giand Q _libe respectively generator reactive power and the reactive load power of node i; G _ijand B _ijbe respectively the conductance between node i and node j and susceptance; θ _ijfor phase difference of voltage between node i and node j; V _i, V _i ^minand V _i ^maxbe respectively the voltage magnitude of node i, voltage minimum and maximum; Q _gi, Q _gi ^minand Q _gi ^maxbe respectively the generator at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; Q _ci, Q _ci ^minand Q _ci ^maxbe respectively the reactive-load compensation equipment at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; T _ki, T _ki ^minand T _ki ^maxbe respectively the on-load tap-changing transformer no-load voltage ratio at node i place, no-load voltage ratio minimum value and maximum;

The Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in power transmission network reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}=f_{i(n+1)}-f_i\≥0\\ f_{2x}=f_i-f_{\mathrm{in}}\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.---2);$

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})=f_{1x}+f_{2x}-\sqrt{{(f_{1x}-f_{2x})}^2+{4\mathrm{\μ}}^2}---3);$

Wherein: f _iit is the first optimal value that i-th on-load tap-changing transformer gear or reactive power compensator switching group number obtain by continuous variable process; f _{i (n+1)}and f _inbe respectively f _ithe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter;

Formula 1), 2), 3) form containing the power transmission network reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

Further, in described step (3), in power transmission network and active distribution network reactive Voltage Optimum alternating iteration process, be the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network using the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network;

Being three-phase voltage by the optimization photovoltaic conversion of power transmission network boundary node in the steps below: be three-phase equilibrium by active distribution network root node voltage sets, is that three-phase phase voltage is tried to achieve by the single-phase optimization photovoltaic conversion of power transmission network orchestration boundary node.

Further, in described step (4), the active distribution network three-phase reactive Voltage Optimum model containing distributed power source is set up in constraint that to take loss minimization as target and node voltage etc. be, adopts solving based on complementary theory and Non-Linear Programming interior point method of process discrete variable; Three-phase reactive Voltage Optimum model containing distributed power source is as follows:

$\min f\left(x\right)=\underset{p\∈\{a,b.c\}}{\mathrm{\Σ}}{f}_p\left(x\right)$

$s.t.{P_i}^p={P_{\mathrm{gi}}}^p-{P_{\mathrm{li}}}^p={V_{\mathrm{ri}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^p+{V_{\mathrm{mi}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

${Q_i}^p={Q_{\mathrm{gi}}}^p-{Q_{\mathrm{li}}}^p={V_{\mathrm{mi}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^P-{V_{\mathrm{ri}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

V _i,p ^min≤V _i,p≤V _i,p ^max

Q _idg,p ^min≤Q _idg,p≤Q _idg,p ^max 4)；

Q _icap,p ^min≤Q _icap,p≤Q _icap,p ^max

T _ik,p ^min≤T _ik,p≤T _ik,p ^max

Wherein: f _px () is the network loss of active distribution network system p phase, p ∈ (a, b, c); F (x) is the network loss of active distribution network system; X=[x ₁ ^t, x ₂ ^t] ^t, wherein x ₁for distributed power source idle exert oneself, the idle of reactive power compensator exert oneself and the no-load voltage ratio column vector of on-load tap-changing transformer, x ₂for real part and the imaginary part column vector of node phase voltage; P _i ^pand Q _i ^pbe respectively injection active power and the reactive power of the p phase of node i; P _gi ^pand P _li ^pbe respectively generator active power and the load active power of the p phase of node i, Q _gi ^pand Q _li ^pbe respectively generator reactive power and the reactive load power of the p phase of node i; V _ri ^pand V _mi ^pbe respectively real part and the imaginary part of the p phase voltage of node i; G _ij ^ptand B _ij ^ptfor the node admittance element between node i and node j, t ∈ (a, b, c); V _i,p, V _i,p ^minand V _i,p ^maxbe respectively the p phase voltage of node i, p phase voltage minimum value and maximum; Q _{idg, p}, Q _{idg, p} ^minand Q _{idg, p} ^maxbe respectively the p phase of i-th distributed power source idlely to exert oneself, p phase is idle exerts oneself minimum value and maximum; Q _{icap, p}, Q _{icap, p} ^minand Q _{icap, p} ^maxbe respectively that the p phase of i-th reactive-load compensation equipment is idlely exerted oneself, p phase is idle and exert oneself minimum value and maximum; T _{ik, p}, T _{ik, p} ^minand T _{ik, p} ^maxbe respectively the p phase no-load voltage ratio of i-th on-load tap-changing transformer, p phase no-load voltage ratio minimum value and maximum;

The Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in active distribution network three-phase reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}={f_{i(n+1)}}^p-{f_i}^p\≥0\\ f_{2x}={f_i}^p-{f_{\mathrm{in}}}^p\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.---5);$

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})={f_{1x}}^p+{f_{2x}}^p-\sqrt{{({f_{1x}}^p-{f_{2x}}^p)}^2+{4\mathrm{\μ}}^2}---6);$

Wherein: f _i ^pit is the first optimal value that i-th on-load tap-changing transformer p phase gear or reactive power compensator p phase switching group number obtain by continuous variable process; f _{i (n+1)} ^pand f _in ^pbe respectively f _i ^pthe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter;

Formula 4), 5), 6) form containing the active distribution network three-phase reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

Further, obtain by described step (2) and step (4) the power transmission network optimum results and the active distribution network three-phase optimum results that comprise transmission and distribution network orchestration boundary node.

Further, in described step (5), in power transmission network and active distribution network reactive Voltage Optimum alternating iteration process, using the load power as power transmission network respective nodes after the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network is sued for peace.

Further, in described step (6), whether the power the judging transmission and distribution network boundary node in an iterative process change of adjacent twice meets convergence precision, if met, forwards to (7), if do not met, forwards (2) to and continue iteration; Convergence precision is the convergence parameter of setting power.

Further, in described step (7), when the change of adjacent twice in iteration of the power of transmission and distribution network boundary node meets convergence precision, power transmission network and active distribution network reactive Voltage Optimum, in the everywhere convergent of transmission and distribution network boundary node, finally obtain Global optimisation strategy.

Compared with the prior art, the beneficial effect that the present invention reaches is:

(1) the present invention is from the angle of overall united analysis, active distribution network adopts triphase flow, consider that active distribution network three-phase imbalance and distributed power source participate in reactive Voltage Optimum, when active distribution network aspect carries out three-phase reactive Voltage Optimum, solve based on the coordination of transmission and distribution network boundary node and complementary Interior-point method, realize the optimization of transmission and distribution network Global, the voltage of the boundary node that solution power transmission network and active distribution network cause when independently calculating and power mismatch, solving transmission and distribution network reactive Voltage Optimum may be inconsistent at the optimum results of transmission and distribution network boundary node, improve the computational accuracy of power system reactive power voltage optimization.

(2) the present invention is from the angle of overall united analysis, when distributed power source participates in reactive Voltage Optimum, optimize the idle resource of power transmission network and active distribution network two-stage, and based on the thought of layering and zoning, mutual by the coordination of power transmission network and active distribution network reactive Voltage Optimum, reach the target of global optimization, the optimization realizing overall idle resource is coordinated, reduce via net loss, improve the quality of voltage of power transmission network and active distribution network.

Accompanying drawing explanation

Fig. 1 is transmission and distribution network Global optimization method flow chart provided by the invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

Transmission and distribution network Global optimization method mainly comprises considers the modeling of active distribution network three-phase, build the coordination interactive frame of power transmission network and the single-phase reactive Voltage Optimum mixed with three-phase of active distribution network, propose the coordination interactive mode of the single-phase reactive Voltage Optimum mixed with three-phase, in active distribution network reactive Voltage Optimum, consider that three-phase imbalance and distributed power source participate in reactive Voltage Optimum, take loss minimization as target, node voltages etc. are for constraint foundation is containing the three-phase reactive Voltage Optimum model of distributed power source, same is target with loss minimization, node voltages etc. set up power transmission network reactive Voltage Optimum model for constraint, power transmission network and active distribution network reactive Voltage Optimum adopt the Algorithm for Solving based on complementary theory and interior point method that can process discrete variable respectively, obtain the power transmission network optimum results and the active distribution network three-phase optimum results that comprise transmission and distribution network boundary node, the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network is the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network by power transmission network and active distribution network reactive Voltage Optimum alternating iteration, using the load power as power transmission network respective nodes after the summation of the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network, under the coordination of transmission and distribution network boundary node, power transmission network and active distribution network reactive Voltage Optimum, in the everywhere convergent of transmission and distribution network boundary node, finally obtain Global optimisation strategy.Transmission and distribution network Global optimization method flow chart as shown in Figure 1, specifically comprises the steps:

(1) selected power transmission network and active distribution network orchestration boundary point: consider the modeling of active distribution network three-phase, build the coordination interactive frame of power transmission network and the single-phase reactive Voltage Optimum mixed with three-phase of active distribution network, propose the coordination interactive mode of the single-phase reactive Voltage Optimum mixed with three-phase.

(2) build power transmission network reactive Voltage Optimum model, adopt Non-Linear Programming interior point method to solve it:

Take loss minimization as target, node voltage etc. for power transmission network reactive Voltage Optimum model is set up in constraint, the method based on complementary theory and Non-Linear Programming interior point method that employing can process discrete variable solves it, and power transmission network reactive Voltage Optimum model is as follows:

min f(x)＝P _l

$s.t.P_i=P_{\mathrm{gi}}-P_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}}+B_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}})$

$Q_i=Q_{\mathrm{gi}}-Q_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}}-B_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}})$

V _i ^min≤V _i≤V _i ^max 1)；

Q _gi ^min≤Q _gi≤Q _gi ^max

Q _ci ^min≤Q _ci≤Q _ci ^max

T _ki ^min≤T _ki≤T _ki ^max

Wherein: P _lfor the network loss of transmission system; N is transmission system nodes; P _iand Q _ibe respectively injection active power and the reactive power of node i; P _giand P _libe respectively generator active power and the load active power of node i; Q _giand Q _libe respectively generator reactive power and the reactive load power of node i; G _ijand B _ijbe respectively the conductance between node i and node j and susceptance; θ _ijfor phase difference of voltage between node i and node j; V _i, V _i ^minand V _i ^maxbe respectively the voltage magnitude of node i, voltage minimum and maximum; Q _gi, Q _gi ^minand Q _gi ^maxbe respectively the generator at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; Q _ci, Q _ci ^minand Q _ci ^maxbe respectively the reactive-load compensation equipment at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; T _ki, T _ki ^minand T _ki ^maxbe respectively the on-load tap-changing transformer no-load voltage ratio at node i place, no-load voltage ratio minimum value and maximum.

In order to process the discrete variable in Mathematical Modeling, the Exact Solution model of discrete variable is built based on complementary theory, adopt document " taking into account the idle work optimization of discrete variable based on the full Smoothing Newton Method of Constraints " (Lin Jikeng, Shi Weizhao, Wu Naihu, Deng. take into account the idle work optimization of discrete variable based on the full Smoothing Newton Method of Constraints. Proceedings of the CSEE, 2012,32 (1): 93-100) method of the structure discrete variable Mathematical Programs With Nonlinear Complementarity Constraints condition in, the Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in power transmission network reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}=f_{i(n+1)}-f_i\≥0\\ f_{2x}=f_i-f_{\mathrm{in}}\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.---2);$

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})=f_{1x}+f_{2x}-\sqrt{{(f_{1x}-f_{2x})}^2+{4\mathrm{\μ}}^2}---3);$

Wherein: f _iit is the first optimal value that i-th on-load tap-changing transformer gear or reactive power compensator switching group number obtain by continuous variable process; f _{i (n+1)}and f _inbe respectively f _ithe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter.

Formula 1), 2), 3) form containing the power transmission network reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

(3) be the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network using the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network.The optimization photovoltaic conversion of power transmission network boundary node is the method for three-phase voltage: be three-phase equilibrium by active distribution network root node voltage sets, is that three-phase phase voltage is tried to achieve by the single-phase optimization photovoltaic conversion of power transmission network boundary node.

(4) in active distribution network reactive Voltage Optimum, consider that three-phase imbalance and distributed power source participate in reactive Voltage Optimum, the three-phase reactive Voltage Optimum model containing distributed power source is set up in constraint that to take loss minimization as target, node voltage etc. be, adopts the method based on complementary theory and Non-Linear Programming interior point method that can process discrete variable to solve it; Three-phase reactive Voltage Optimum model containing distributed power source is as follows:

$\min f\left(x\right)=\underset{p\∈\{a,b.c\}}{\mathrm{\Σ}}{f}_p\left(x\right)$

$s.t.{P_i}^p={P_{\mathrm{gi}}}^p-{P_{\mathrm{li}}}^p={V_{\mathrm{ri}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^p+{V_{\mathrm{mi}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

${Q_i}^p={Q_{\mathrm{gi}}}^p-{Q_{\mathrm{li}}}^p={V_{\mathrm{mi}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^P-{V_{\mathrm{ri}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

V _i,p ^min≤V _i,p≤V _i,p ^max

Q _idg,p ^min≤Q _idg,p≤Q _idg,p ^max 4)；

Q _icap,p ^min≤Q _icap,p≤Q _icap,p ^max

T _ik,p ^min≤T _ik,p≤T _ik,p ^max

Wherein: f _px () is the network loss of active distribution network system p phase, p ∈ (a, b, c); F (x) is the network loss of active distribution network system; X=[x ₁ ^t, x ₂ ^t] ^t, x ₁for distributed power source idle exert oneself, the idle of reactive power compensator exert oneself and the no-load voltage ratio column vector of on-load tap-changing transformer, x ₂for real part and the imaginary part column vector of node phase voltage; P _i ^pand Q _i ^pbe respectively injection active power and the reactive power of the p phase of node i; P _gi ^pand P _li ^pbe respectively generator active power and the load active power of the p phase of node i, Q _gi ^pand Q _li ^pbe respectively generator reactive power and the reactive load power of the p phase of node i; Formula 4) in power-balance equality constraint equation list of references " Three-phase power flow calculations using the current injection method " (Paulo A.N.Garcia, Jose Luiz R.Pereira, Sandoval Carneiro, Jr., et al.Three-phase power flow calculations using the current injection method.IEEE TRANSACTIONS ON POWER SYSTEMS, 2000,15 (2): 508-514).V _ri ^pand V _mi ^pbe respectively real part and the imaginary part of the p phase voltage of node i; G _ij ^ptand B _ij ^ptfor the node admittance element between node i and node j, t ∈ (a, b, c); V _i,p, V _i,p ^minand V _i,p ^maxbe respectively the p phase voltage of node i, p phase voltage minimum value and maximum; Q _{idg, p}, Q _{idg, p} ^minand Q _{idg, p} ^maxbe respectively the p phase of i-th distributed power source idlely to exert oneself, p phase is idle exerts oneself minimum value and maximum; Q _{icap, p}, Q _{icap, p} ^minand Q _{icap, p} ^maxbe respectively that the p phase of i-th reactive-load compensation equipment is idlely exerted oneself, p phase is idle and exert oneself minimum value and maximum; T _{ik, p}, T _{ik, p} ^minand T _{ik, p} ^maxbe respectively the p phase no-load voltage ratio of i-th on-load tap-changing transformer, p phase no-load voltage ratio minimum value and maximum;

In order to process the discrete variable in Mathematical Modeling, the Exact Solution model of discrete variable is built based on complementary theory, adopt document " taking into account the idle work optimization of discrete variable based on the full Smoothing Newton Method of Constraints " (Lin Jikeng, Shi Weizhao, Wu Naihu, Deng. take into account the idle work optimization of discrete variable based on the full Smoothing Newton Method of Constraints. Proceedings of the CSEE, 2012, 32 (1): 93-100) method of the structure discrete variable Mathematical Programs With Nonlinear Complementarity Constraints condition in, the Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in active distribution network three-phase reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}={f_{i(n+1)}}^p-{f_i}^p\≥0\\ f_{2x}={f_i}^p-{f_{\mathrm{in}}}^p\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.---5);$

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})={f_{1x}}^p+{f_{2x}}^p-\sqrt{{({f_{1x}}^p-{f_{2x}}^p)}^2+{4\mathrm{\μ}}^2}---6);$

Wherein: f _i ^pit is the first optimal value that i-th on-load tap-changing transformer p phase gear or reactive power compensator p phase switching group number obtain by continuous variable process; f _{i (n+1)} ^pand f _in ^pbe respectively f _i ^pthe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter;

Formula 4), 5), 6) form containing the active distribution network three-phase reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

The power transmission network optimum results and the active distribution network three-phase optimum results that comprise transmission and distribution network orchestration boundary node is obtained by described step (2) and step (4).

(5) using the load power as power transmission network respective nodes after the summation of the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network.

(6) power transmission network and active distribution network reactive Voltage Optimum alternating iteration, under the coordination of transmission and distribution network boundary node, whether the change of adjacent twice meets convergence precision to judge the power of transmission and distribution network boundary node in iteration, if met, forward to (7), if do not met, forward (2) to and continue iteration; Convergence precision needs to set according to different computational accuracies.

(7) power transmission network and active distribution network reactive Voltage Optimum are in the everywhere convergent of transmission and distribution network boundary node, finally obtain Global optimisation strategy.

The present invention is from the angle of overall united analysis, active distribution network aspect considers that the three-phase imbalance of power distribution network and distributed power source participate in reactive Voltage Optimum, adopt triphase flow, when carrying out active distribution network three-phase reactive Voltage Optimum, coordinate to solve with the complementary Interior-point method that can process discrete variable based on transmission and distribution network boundary node, a kind of transmission and distribution network Global optimization method is proposed, optimize the idle resource of power transmission network and active distribution network, mutual by the coordination of power transmission network and active distribution network reactive Voltage Optimum, solve the problem, the optimization simultaneously realizing overall idle resource is coordinated, reduce via net loss, improve the quality of voltage of power transmission network and active distribution network.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; although with reference to above-described embodiment to invention has been detailed description; those of ordinary skill in the field still can modify to the specific embodiment of the present invention or equivalent replacement; these do not depart from any amendment of spirit and scope of the invention or equivalent replacement, are all applying within the claims of the present invention awaited the reply.

Claims (9)

1. a transmission and distribution network Global optimization method, is characterized in that, described method comprises the steps:

(1) selected power transmission network and active distribution network orchestration boundary point;

(2) build the power transmission network reactive Voltage Optimum model containing Constraints condition, adopt Non-Linear Programming interior point method to solve it;

(3) be the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network using the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network;

(4) build the three-phase reactive Voltage Optimum model containing Constraints condition of the active distribution network containing distributed power source, adopt Non-Linear Programming interior point method to solve it;

(5) using the load power as power transmission network respective nodes after the summation of the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network;

(6) whether the power the judging transmission and distribution network boundary node in an iterative process change of adjacent twice meets convergence precision;

(7) convergence at transmission and distribution network boundary node place according to power transmission network and active distribution network reactive Voltage Optimum, obtains Global optimisation strategy.

2. Global optimization method as claimed in claim 1, it is characterized in that, in described step (1), selected power transmission network and active distribution network orchestration boundary node, to the modeling of active distribution network three-phase, build the coordination interactive frame of power transmission network and the single-phase reactive Voltage Optimum mixed with three-phase of active distribution network, and the coordination interactive mode of the single-phase reactive Voltage Optimum mixed with three-phase.

3. Global optimization method as claimed in claim 1, it is characterized in that, in described step (2), take loss minimization as target, node voltage sets up power transmission network reactive Voltage Optimum model for constraint, adopt the method based on complementary theory and Non-Linear Programming interior point method that can process discrete variable to solve it; Power transmission network reactive Voltage Optimum model is as follows:

minf(x)＝P _l

$s.t.P_i=P_{\mathrm{gi}}-P_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}}+B_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}})$

$Q_i=Q_{\mathrm{gi}}-Q_{\mathrm{li}}=V_i\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{V}_j(G_{\mathrm{ij}}\sin {\mathrm{\θ}}_{\mathrm{ij}}-B_{\mathrm{ij}}\cos {\mathrm{\θ}}_{\mathrm{ij}})$ 1)；

V _i ^min≤V _i≤V _i ^max

Q _gi ^min≤Q _gi≤Q _gi ^max

Q _ci ^min≤Q _ci≤Q _ci ^max

T _ki ^min≤T _ki≤T _ki ^max

Wherein: P _lfor the network loss of transmission system; N is transmission system nodes; P _iand Q _ibe respectively injection active power and the reactive power of node i; P _giand P _libe respectively generator active power and the load active power of node i; Q _giand Q _libe respectively generator reactive power and the reactive load power of node i; G _ijand B _ijbe respectively the conductance between node i and node j and susceptance; θ _ijfor phase difference of voltage between node i and node j; V _i, V _i ^minand V _i ^maxbe respectively the voltage magnitude of node i, voltage minimum and maximum; Q _gi, Q _gi ^minand Q _gi ^maxbe respectively the generator at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; Q _ci, Q _ci ^minand Q _ci ^maxbe respectively the reactive-load compensation equipment at node i place idlely to exert oneself, idle minimum value and the maximum of exerting oneself; T _ki, T _ki ^minand T _ki ^maxbe respectively the on-load tap-changing transformer no-load voltage ratio at node i place, no-load voltage ratio minimum value and maximum;

The Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in power transmission network reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}=f_{i(n+1)}-f_i\≥0\\ f_{2x}=f_i-f_{\mathrm{in}}\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.$ 2)；

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})=f_{1x}+f_{2x}-\sqrt{{(f_{1x}-f_{2x})}^2+4{\mathrm{\μ}}^2}$ 3)；

Wherein: f _iit is the first optimal value that i-th on-load tap-changing transformer gear or reactive power compensator switching group number obtain by continuous variable process; f _{i (n+1)}and f _inbe respectively f _ithe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter;

Formula 1), 2), 3) form containing the power transmission network reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

4. Global optimization method as claimed in claim 1, it is characterized in that, in described step (3), in power transmission network and active distribution network reactive Voltage Optimum alternating iteration process, be the three-phase voltage of three-phase voltage as the corresponding root node of active distribution network using the optimization photovoltaic conversion of transmission and distribution network boundary node each in power transmission network;

Being three-phase voltage by the optimization photovoltaic conversion of power transmission network boundary node in the steps below: be three-phase equilibrium by active distribution network root node voltage sets, is that three-phase phase voltage is tried to achieve by the single-phase optimization photovoltaic conversion of power transmission network orchestration boundary node.

5. Global optimization method as claimed in claim 1, it is characterized in that, in described step (4), take loss minimization as target, node voltage sets up containing the active distribution network three-phase reactive Voltage Optimum model of distributed power source for constraint, adopt solving based on complementary theory and Non-Linear Programming interior point method of process discrete variable; Three-phase reactive Voltage Optimum model containing distributed power source is as follows:

$\min f\left(x\right)=\underset{p\∈\{a,b,c\}}{\mathrm{\Σ}}{f}_p\left(x\right)$

$s.t.{P_i}^p={P_{\mathrm{gi}}}^p-{P_{\mathrm{li}}}^p={V_{\mathrm{ri}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^p+{V_{\mathrm{mi}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

${Q_i}^p={Q_{\mathrm{gi}}}^p-{Q_{\mathrm{li}}}^p={V_{\mathrm{mi}}}^p(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\underset{t\∈\{a,b,c\}}{\mathrm{\Σ}}{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t)}^p-{V_{\mathrm{ri}}}^p{({G_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{mj}}}^t-{B_{\mathrm{ij}}}^{\mathrm{pt}}{V_{\mathrm{rj}}}^t)}^p$

V _i,p ^min≤V _i,p≤V _i,p ^max

4)；

Q _idg,p ^min≤Q _idg,p≤Q _idg,p ^max

Q _icap,p ^min≤Q _icap,p≤Q _icap,p ^max

T _ik,p ^min≤T _ik,p≤T _ik,p ^max

Wherein: f _px () is the network loss of active distribution network system p phase, p ∈ (a, b, c); F (x) is the network loss of active distribution network system; X=[x ₁ ^t, x ₂ ^t] ^t, wherein x ₁for distributed power source idle exert oneself, the idle of reactive power compensator exert oneself and the no-load voltage ratio column vector of on-load tap-changing transformer, x ₂for real part and the imaginary part column vector of node phase voltage; P _i ^pand Q _i ^pbe respectively injection active power and the reactive power of the p phase of node i; P _gi ^pand P _li ^pbe respectively generator active power and the load active power of the p phase of node i, Q _gi ^pand Q _li ^pbe respectively generator reactive power and the reactive load power of the p phase of node i; V _ri ^pand V _mi ^pbe respectively real part and the imaginary part of the p phase voltage of node i; G _ij ^ptand B _ij ^ptfor the node admittance element between node i and node j, t ∈ (a, b, c); V _i,p, V _i,p ^minand V _i,p ^maxbe respectively the p phase voltage of node i, p phase voltage minimum value and maximum; Q _{idg, p}, Q _{idg, p} ^minand Q _{idg, p} ^maxbe respectively the p phase of i-th distributed power source idlely to exert oneself, p phase is idle exerts oneself minimum value and maximum; Q _{icap, p}, Q _{icap, p} ^minand Q _{icap, p} ^maxbe respectively that the p phase of i-th reactive-load compensation equipment is idlely exerted oneself, p phase is idle and exert oneself minimum value and maximum; T _{ik, p}, T _{ik, p} ^minand T _{ik, p} ^maxbe respectively the p phase no-load voltage ratio of i-th on-load tap-changing transformer, p phase no-load voltage ratio minimum value and maximum;

The Mathematical Programs With Nonlinear Complementarity Constraints condition building discrete variable in active distribution network three-phase reactive Voltage Optimum is as follows:

$\left\{\begin{array}{c}{f}_{1x}={f_{i(n+1)}}^p-{f_i}^p\≥0\\ f_{2x}={f_i}^p-{f_{\mathrm{in}}}^p\≥0\\ f_{1x}{f}_{2x}=0\end{array}\right.$ 5)；

$\mathrm{\ψ}(\mathrm{\μ},f_{1x},f_{2x})={f_{1x}}^p+{f_{2x}}^p-\sqrt{{({f_{1x}}^p-{f_{2x}}^p)}^2+4{\mathrm{\μ}}^2}$ 6)；

Wherein: f _i ^pit is the first optimal value that i-th on-load tap-changing transformer p phase gear or reactive power compensator p phase switching group number obtain by continuous variable process; f _{i (n+1)} ^pand f _in ^pbe respectively f _i ^pthe actual-gear of left and right or switching group number; f _1xand f _2xfor intermediate variable; μ is smoothing parameter;

Formula 4), 5), 6) form containing the active distribution network three-phase reactive Voltage Optimum model of Constraints condition, adopt Non-Linear Programming interior point method to solve.

6. Global optimization method as claimed in claim 1, it is characterized in that, obtain by described step (2) and step (4) the power transmission network optimum results and the active distribution network three-phase optimum results that comprise transmission and distribution network orchestration boundary node.

7. Global optimization method as claimed in claim 1, it is characterized in that, in described step (5), in power transmission network and active distribution network reactive Voltage Optimum alternating iteration process, using the load power as power transmission network respective nodes after the three-phase optimizing power of transmission and distribution network boundary node each in active distribution network is sued for peace.

8. Global optimization method as claimed in claim 1, it is characterized in that, in described step (6), whether the power the judging transmission and distribution network boundary node in an iterative process change of adjacent twice meets convergence precision, if met, forward to (7), if do not met, forward (2) to and continue iteration; Convergence precision is the convergence parameter of setting power.

9. Global optimization method as claimed in claim 1, it is characterized in that, in described step (7), when the change of adjacent twice in iteration of the power of transmission and distribution network boundary node meets convergence precision, power transmission network and active distribution network reactive Voltage Optimum, in the everywhere convergent of transmission and distribution network boundary node, finally obtain Global optimisation strategy.